Q690高强钢脉冲MAG焊接头的组织与性能  

Microstructure and Properties of Plused-MAG Welded Joint of Q690 High Strength Steel

作　　者：杜宝帅 索帅 张忠文 李新梅 邓化凌 DU Baoshuai;SUO Shuai;ZHANG Zhongwen;LI Xinmei;DENG Hualing(State Grid Shandong Electric Power Research Institute,Ji'nan 250002,China;Shandong Electric Power Industry Boiler&Pressure Vessel Inspection Center Co.,Ltd.,Ji'nan 250002,China)

机构地区：[1]国网山东省电力公司电力科学研究院,山东济南250002 [2]山东电力工业锅炉压力容器检验中心有限公司,山东济南250002

出　　处：《热加工工艺》2020年第19期48-51,共4页Hot Working Technology

摘　　要：选择ER69-G焊丝,采用脉冲MAG焊制备了Q690焊接接头。利用金相显微镜、扫描电镜、能谱仪、万能材料试验机、冲击试验机测试分析了焊接接头的显微组织与力学性能。结果表明,焊缝金属为针状铁素体,热影响区粗晶区为粒状贝氏体,相变重结晶区及不完全重结晶区中原贝氏体组织转变为多边形铁素体。采用脉冲MAG焊制备的焊接接头具有良好的强度和塑韧性。焊接接头的热影响区受热循环作用发生软化现象,是整个接头中强度及韧性的薄弱环节。Q690 welded joint was fabricated by pulse MAG welding and using ER69-G welding wire. Metallugical microscopy, scanning electron microscopy, energy dispersive spectroscopy, universal materials tester, and impact tester were used to test and analyze the microstructure and mechanical properties of the welded joint. The results show that the microstructure of welding metal consists of acicular ferrite, while granular banite forms in the coarse-grained region of heat affected zone. Banite in the fully-transformed and partly-transformed region changes into polygonal ferrite. The welded joint fabricated by pulse MAG possesses good combination of strength and ductility. Due to the soften phenomenon under the heating cycle, the heat affected zone is the weak part in terms of strength and ductility of the welded joint.

关 键 词：Q690 脉冲MAG焊 焊接接头 组织 性能 

分 类 号：TG444.77[金属学及工艺—焊接]